A conventional Low-Noise Amplifier (LNA) is an electronic amplifier that amplifies a very low-voltage input signal into an output signal without significantly degrading its signal-to-noise ratio. As a specific example, depending on a respective gain setting, an amplifier circuit produces a higher magnitude replica of the input signal, preferably with limited noise amplification.
Conventional LNA circuitry used in mobile communication devices typically support a so-called “linearity on demand” feature, which requires the implementation of different gain step modes. One of these modes is the so-called “High Gain Mode”, which uses the maximum allowed current to achieve best gain and noise figure performance from the input to the output. Proper operation and performance of a communication device typically depends on the ability of the amplifier circuit to provide appropriate gain.
FIG. 1 is an example diagram illustrating a conventional amplifier circuit operating based on a power supply (such as a VDD) of 1.8 volts DC. In general, during operation, the input stage 110 of the amplifier 100 produces the signal 120. Output stage 130 receives the signal 120 from the input stage 110 as input and produces the output signal Vout. The output voltage, Vout, is an amplified rendition of the input voltage Vin.